Analysis of the Upper Devonian Munster Basin, an Example of a Fluvial Distributary System

  1. J. D. Collinson and
  2. J. Lewin
  1. John R. Graham

Published Online: 29 APR 2009

DOI: 10.1002/9781444303773.ch38

Modern and Ancient Fluvial Systems

Modern and Ancient Fluvial Systems

How to Cite

Graham, J. R. (1983) Analysis of the Upper Devonian Munster Basin, an Example of a Fluvial Distributary System, in Modern and Ancient Fluvial Systems (eds J. D. Collinson and J. Lewin), Blackwell Publishing Ltd., Oxford, UK. doi: 10.1002/9781444303773.ch38

Author Information

  1. Department of Geology, Trinity College, Dublin 2, Ireland

Publication History

  1. Published Online: 29 APR 2009
  2. Published Print: 7 FEB 1983

ISBN Information

Print ISBN: 9780632009978

Online ISBN: 9781444303773

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Keywords:

  • analysis of upper Devonian Munster basin – fluvial distributary system;
  • basin fill;
  • sandstone bodies;
  • bioturbation;
  • orogenic factors

Summary

The Munster Basin, covering an area of more than 12,500 km2, was the site of fluvial sedimentation during the Upper Devonian. The basin was of half-graben style, with a faulted northern margin and a maximum thickness of 6–7 km just to the south of this margin. There is evidence for an eastern basin margin separating this area from the Anglo-Welsh basin, and some indication from palaeocurrents of a western margin. The southern margin cannot presently be determined and an original southward connection to marine strata is uncertain.

The basin fill is described in terms of four major facies: (a) a localized coarse marginal facies with alluvial fans and, more rarely, aeolian sediments, (b) a coarse-grained fluvial facies dominated by ‘in channel’ deposition, (c) a fine-grained fluvial facies with rare or poorly defined channels, (d) a fluvial coastal plain facies. Facies (d) occurs only at the top of the succession and represents time-dependent changes associated with the major Tournaisian transgression. For most of the Upper Devonian facies (b) and (c) predominate, with facies (b) occupying the more marginal and facies (c) more central parts of the basin. The facies pattern is best explained by means of a major fluvial distributary system. Although there was a local input of sediment from the basin margins the petrography generally indicates a distant source.